1. Field of the Invention
The present invention is concerned with an apparatus for trimming a layer of fat off a piece of meat, in particular but not exclusively a layer of back fat off a pork shoulder butt, for example of the Boston style.
2. Brief Description of the Prior Art
An apparatus of the above type is described in U.S. Pat. No. 3,546,737 (NEEBEL ET AL.) issued on Dec. 15, 1970. This prior art apparatus comprises a conveyor for receiving an animal side, more particularly a pork side, and for conveying it through a knife in the form of a U-shaped, flat flexible cutting blade. The pork side is positioned onto the conveyor with the backbone up and the thicker end thereof is forced against a side rail; the pork side is held in this position during transport thereof onto the conveyor. A first end of the flexible blade is pivotally mounted onto a mechanical linkage itself pivotally attached to the frame of the apparatus, while the second end of this blade is fixedly secured to an mechanical assembly rotatable about a vertical shaft. As the pork side is conveyed, the first end of the blade is moved laterally and vertically through pivoting of the mechanical linkage while the second end thereof is twisted and moved backward through rotation of the mechanical assembly to thereby enable the knife to follow the inner profile of the layer of back fat on the pork side whereby trimming of this fat layer is optimized.
A drawback of the apparatus of U.S. Pat. No. 3,546,737 is the complexity of its structure and operation due to the contemplated application, namely to trim the back fat off an entire pork side; one end of the blade is moved laterally and vertically while the other end thereof is twisted and displaced backward to follow the inner profile of the layer of fat. In addition, a side rail and other elements associated therewith are required to position the pork side as it is conveyed through the blade. Obviously, the conveyor of NEEBEL et al. also lacks efficiency in forcing the pork side through the knife blade.